The resolution to this tension is that in general, a polynomial is not a function. You can associate a function with a polynomial by evaluating the polynomial for some value of x, but two different polynomials may correspond to the same function.

Illustrating the mediant inequality with batting averages and giving a simple proof.

How would you attack a pass code entered into a keypad without an "enter" key? Would requiring an enter key improve security more than requiring another digit?